At constant temperature, the rate of adsorption increases with increase in pressure. So (i) is a favorable condition for adsorption.

Adsorption is an exothermic process, so ΔH is negative. Therefore, option (ii) is also favorable for adsorption.

Higher critical temperature of adsorbate increases the rate of adsorption. So (iii) is also true condition for adsorption.

At high temperature, the amount of gas adsorbed get decrease. So high temperature is not a favorable condition for adsorption. Therefore option (iv) is correct.